The objective of this research is to investigate the effectiveness of supplemental sensory feedback (SSF) systems using mild electrical stimulation of the skin as an aid to the patient in controlling upper limb prostheses and orthoses. The following nine task research proram is in pogress: (1) Design and develope SSF systems for artificial limbs; (2) Conduct basic and applied research studies of electrocutaneous stimulation parameters; (3) Investigate the effectiveness of SSF related to various parameters of a prosthesis/orthosis and its environment; (4) Clinically evaluate prototype SSF system for artificial arms developed in task 1; (5) Refine and clinically evaluate harness mounted proportional controllers/electrocutaneous SSF packages for use with commercially available switch-controlled hands and elbows; (6) Design and evaluate a prosthetic control harness for use by non-amputee researchers in developing artificial arms; (7) Determine the feasibility of a proportionally controlled linear power assist device for body powered cable operated above elbow prostheses; (8) Develop a four degree offreedom microcomputer aided prosthesis with electrocutaneous feedback; and (9) Develop a computer controlled lectrocutaneous stimulator and graphics display (COMSTIM) with prosthetic limb/orthotic brace/environmental interfaces (LIMBFACE). Guidelines for designing electrocutaneous sensory feedback packages for upper limb prostheses and orthoses are being established and information for related applications in other areas provided. The feasibility and utility of prosthetic/orthotic devices with electrocutaneous feedback are being ascertained through careful experimental evaluation on amputees and neuromuscularly handicapped individuals. BIBLIOGRAPHIC REFERENCES: Prior, R.E., P.A. Case, C.M. Scott, and J. Lyman, "A Myoelectric Hand with Supplemental Sensory Feedback," Proceedings of the San Diego Biomedical Symposium, 15:91-103, San Diego, California, February 4-6, 1976. Prior, R.E., P.A. Case, and J. Lyman, "Hook Opening Feedback for the Below Elbow Amputee," to be presented at the San Diego Biomedical Symposium and published in the Proceedings, February 2-4, 1977.